Determine in which direction the parabola opens y=-3x^2+5x+11 up down left right

We have that
y=-3x²+5x+11

we know that
the equation of the parabola in standard form can be expressed in one of the following two ways
y=ax²+bx+c
the parabola opens up if a is positive and opens down if a is negative
and
x=ay²+by+c
the parabola opens right if a is positive and opens left if a is negative

in this problem 
the equation is of the form
y=ax²+bx+c
a=-3
so
the parabola opens down

using a graph tool
see the attached figure
the vertex of a parabola is a maximum

the answer is
the parabola opens down

A= b/2 because u simplying both sides of equation

Aquadratic function is one of the form f(x)=ax2 + bx + c l, where a,b, and c are numbers with are not equal to zero.